This invention concerns the pipe machining industry and, in particular, pipe cutting, and refers in particular, but not only, to machines for cutting continuously manufactured pipes to be cut in specific lengths during pipe feed.
Standard procedures for manufacturing pipes or cylindrical bodies in general envisage both the so-called xe2x80x9ccontinuous productionsxe2x80x9d, and the production of pipes in sections, including those made from suitably bent and welded plate metal.
With respect to the cutting operations, these can be performed using special blade or cutting disk equipment, or using a more modern method, by using laser beams.
Within the framework of this latter solution, for instance in patent EP 0 808 685 A2, laser cutting units have already been presented for pipes made in continuous, substantially comprising a laser source, a sliding carriage, driven by a motor on rails placed parallel to the direction of feed of the pipe to be cut and, on such carriage, a devices for securing the carriage to the pipe and two or more hollow arms turning on parallel tables and perpendicular to the direction of pipe feed, said arms featuring mirrors at one or both ends to suitably reflect and direct the beam exiting from the laser emitter towards a focalisation head rotating around the pipe. The laser source can be mounted on-board the carriage or be fixed, placed alongside the pipe former so as to project the laser beam parallel to the pipe being formed.
Such cutting units nonetheless can only be used with round-section pipes because the movement of the focalisation head is designed to follow a constant trajectory with circular movement around the pipe. This requirement derives from the fact that the laser beam must always be directed at right angles on the surface to be cut and on which it is projected to obtain a precise and already finished cut, this method of operation not therefore being applicable to pipes with other than round cross section.
Further limitations of traditional laser cutting devices are the impossibility of working pipes of different diameter, including to an extensive degree.
The purpose of this invention is to eliminate the problems and limitations referred to above by adopting a machine for cutting pipes by means of a laser beam in conformity with claim 1.